Gas mask equipment



July 12, 1938. F. c. MlLLARD mks MASK EQUIPMENT Filed Nov. 23, 1936 1? INVENTOR.

FEEDEE/CK fl/V/LLHRD gw ATTORNEY d Patented July 12, 1938 UNITED sr GAS MASK EQUIPMENT Pennsylvania Application November 23, 1936, Serial No. 112,254

3 Claims.

The invention relates to gas masks, and particularly to sound transmitting means permitting the voice of the wearer of a mask to be transmitted without any loss of volume or clearness.

Heretofore attempts to secure this result have involved the use of diaphragms seated in the front walls of the masks whose vibrations as produced by the voice of the wearer of the mask were communicated to the air outside the mask.

While these devices give some assistance in sound transmission, the volume is cut down to a rela- -'tively small fractionof the sound produced in the mask, and the communication of sound by one wearing the mask is very limited in range,

16 and involves great-eflort on the part of the speaker. The object of the present invention is to provide sound transmission equipment which adds only a negligible amount of weight to the mask itself; which permits 01 the transmission so of the voice of the wearer of the mask without any decrease in volume or clearness: and which. in fact, gives the voice a greater volume and range than if no mask were used. Briefly stated,

this is accomplished by the use or a telephone transmitter in the wall of the mask to which a dynamic speaker is connected, such speaker being suitably supported on the person 0! the wearer o! the mask. Such speaker, and the necessary battery, are preferably mounted in the canister 3o carrier which is attached to a belt or other suitable harness. when usedin this way, the additional weight involved is hardly noticeable, and the equipment may be appli'edfand worn without any greater inconvenience than standard equipv .ment. The equipment is particularly designed for the use or oillcers in command of bodies of troops to whom orders must be issued from time to time, and for the use oi industrial workers who must communicate back and forth in per- 4 forming duties which require gas mask protection. One embodiment of the invention is shown in the accompanying drawing, wherein:

Flgurelisairontviewoithemaskand equipment. Fig. 2 is a partial 'side elevation and partialsectiononanenlargedscale. AndFIiLS is a wiring diagram.

Reierringtothedrawinsdisthebodyoithe mask, preferably 01' molded rubber and provided with the usual holding straps]. the flutter valve tandeyepieces I; iisaboxorcarrier torthe canister 8: and i0 isthehose connection leading from the cannister to the cavity of the mask.

Formed integrally with the mask. is a casing II which carries the telephone transmitter. The 55 transmitter is o! the carbon granule type and includes the diaphragm l2 opposite the mouth 01 the wearer oi the mask and'the box I! carrying the granular carbon, said box being suitabiysupported in opposition to the diaphragm. A perforated shield H lies in front of the diaphragm. Mounted in the box 8 at one side of the canister is a dynamic speaker comprising the coil II and 6 magnet bar It. Also mounted in the carrier is a suitable battery ll i'or supplying current to the circuit, such circuit being shown in-Flg. 3, wherein l8 and I9 are the connecting wires and 20 is a suitable switch. The wires are preferably 10 arranged in a single cable and connected to the diaphragm and box, so that the granular carbon in the box l3 forms a part of thecircuit. The construction and operation of a carbon granule transmitter and dynamic speaker are well known 15 in the electrical art, so that no detailed description is required. An equipment of this type with properly selected transmitting and speaker units will give a sound transmission of such volume that the voice of the wearer of the mask will be somewhat amplified. As a result, the sound transmission is helped rather than hindered by the use of the equipment. The amplification o! the sound is due in part to the use of the carbon granule transmitter, and in part to the speaker unit, the volume of sound being subject to increase upon an increase in the voltage oi the battery employed and the diameter of the diaphragm oi the speaker.

What I claim is: so

1. In combination with a gas mask, a tele@ phone transmitter with its diaphragm seated in the wall thereof to receive the sound waves from the mouth oi the wearer,- an electro-dynamic loud speaker and battery in proximity to the mask and portable therewith adapted ,to be carried .by ,the wearer. and wiring connections between the transmitter, battery and dynamic speaker. v

2. In combination with a gas mask. a telephone transmitter oi the carbon granule type carried by the mask and including a diaphragm mounted in the wall thereof in opposition to the mouth of .the wearer oi the mask, an eiectro-dynamic loud speaker and battery in proximity to the mask and portable therewith adapted to be carried by the wearer, and wiring connections "between the transmitter, battery and dynamic speaker.

3. In combination with a gas mask. a canister, a carrier therefor and an inlet connection ior air leading through the canister, a telephone transmitter with its diaphragm seated in the wall of the mask, a dynamic speaker and battery supported by the carrier, and wiring connections between the transmitter battery and dynamic speaker.

msnsatck c. mum. 

